Related Experiment Videos
Transition from dynamically maintained to relaxed end-expiratory volume in human infants
1Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|November 1, 1989
Summary
Infants develop a relaxed breathing strategy, maintaining end-expiratory lung volume (EEV) above relaxation volume, by the end of their first year. This shift from interrupted breathing is linked to growth and respiratory timing changes.
Area of Science:
- Pediatric respiratory physiology
- Developmental biology
Background:
- Newborn infants maintain end-expiratory lung volume (EEV) dynamically above relaxation volume, unlike adults.
- Understanding the developmental timeline of relaxed breathing strategies in children is crucial for assessing respiratory health.
Purpose of the Study:
- To determine the age at which healthy children develop a relaxed breathing strategy.
- To identify the age when breathing becomes determined by lung and chest wall mechanics.
Main Methods:
- Respiratory inductance plethysmography (RIP) recorded volume changes in 27 healthy infants and children (1 mo to 8 yr) during sleep.
- Flow-volume loops analyzed breathing patterns (relaxed, interrupted, indeterminate).
Main Results:
- Breathing patterns were predominantly interrupted in infants under 6 months.
- A relaxed breathing pattern emerged in children over 1 year of age, with mixed patterns in between.
- Respiratory frequency decreased with age, while expiratory time increased.
Conclusions:
- A relaxed end-expiratory lung volume (EEV) strategy develops by the end of the first year of life.
- This developmental milestone may be associated with changes in chest wall mechanics and respiratory timing.